Heat transfer unit and system



Dec. 9, 1941.

Q. E. MEYERHOEFER HEAT TRANSFER UNIT AND SYSTEM Filed A ril 2, 193a 2Sheets-Sheet 1 ATTORN YS Dec. 9, 1941- c. E. MEYERHOEFER HEAT TRANSFERUNIT AND SYSTEM Filed April 2, 1938 ZSheets-Sheet 2 u n I u a a PatentedDec. 9, 1941 HEAT TRANSFER UNIT AND SYSTEM Carl E. Meyerhoefer,Brooklyn, N. Y., assignor to E. A. Laboratories, Inc., Brooklyn, N. Y.,a. corporation of New York Application April 2, 1938, Serial No. 199,574

3 Claims.

This invention relates to a structurally and functionally improved heattransfer unit and system and while the same is capable of use innumerous different associations, it is primarily intended to be employedfor the conditioning of air within an enclosure such as the body of amotor vehicle.

Whether employed in this or functionally equivalent installations, it isintended to furnish a unit and set-up of apparatus which may eitherraise or lower the dry bulb temperature of an enclosure and which systemwill be of such a simple nature that it may be installed by a mechanicof ordinary skill and will operate without virtually any attention orskilled supervision.

It is an object of the invention to provide a structure such that amaximum heat transfer will be accomplished, the system operating forexample with heated water, secured from the cooling system of aninternal combustion motorwhen it is desired to raise the dry bulbtemperatureand functioning with one of any number of desirablerefrigerants when it is intended to reduce the dry bulb temperature.

A further object of the invention is that of furnishing a structure ofthis nature and in which the refrigerant will, at all times, be properlymaintained so that the system will operate with maximum efficiency.

A still further object is that of providing a set-up of apparatus whichwill be of an extremely simple and compact nature, readily capable ofbeing associated with and acccommodated within an automobile, the partsbeing individually simple and rugged in construction, and capable ofassemblage by unskilled labor to furnish a unitary and economical systemof this type.

According to certain further aspects, the present invention contemplatesan improved or alternative structure to that described and shown in myprevious application for patent which resulted in United States PatentNo. 2,118,263, on

May 24, 1938, and identified under the title of Heat transfer apparatus.

With these and other objects in mind, reference is had to the attachedsheets of drawings illustrating practical embodiments of the inventionand in which:-

Fig. 1 is a view showing diagrammatically the motor of a vehicle andillustrating the system in association therewith;

Fig. 2 is a front elevation of the heat transfer unit and theconnections extending therefrom;

Fig. 3 is a transverse sectional view taken along the lines 3--3 and inthe direction of the arrows of Fig. 2;

Fig. 4 is a sectional plan view taken along the lines 4-4 and in thedirection of the arrows of Fig. 2;

Fig. 5 is an enlarged sectional side view taken along the lines 5-"-5and, in the direction of the arrows of Fig. 3; i

Fig. 6 is a view similar to Fig. 5, but showing an alternative form ofconstruction;

Fig. '7 is a cross section through the heat transfer unit shown in Fig.5 taken along the line '|-1 in that view and in the direction of thearrows,

and

Fig. 8 is a section taken through the heat transfer unit shown in Fig. 6along the line 8-8 of that section and again in the direction of thearrows.

The subject matter of the system particularly shown in Figs. 1 to 4inclusive and as hereinafter described, has been included in divisionalapplication for United States Letters Patent 231,348 for Cooling systemfiled September 23, 1938.

Before continuing with a consideration of. the structure heretoforebriefly'described, it is to be understood that while in many respectsthe present invention is primarily intended for association with a motorvehicle, it might be employed in numerous other instances and whereverit is necessary or desired to effect heat exchange, and particularly thelowering of air temperatures. Thus, the present drawings and descriptionare to be construed in an illustrative, and not in a limiting sense,except where otherwise indicated in the appended claims.

Thus, referring primarily to Fig. l, the numeral l0 indicates a motorprovided with the usual cooling system from which tubes l l and I2extend to the radiator l3. To the rear of the motor there is providedthe conventional partition or dash I4 upon which is mounted a heattransfer unit generally indicated at 15, including air passages throughwhich air is forced in heat exchange contact by means of a suitablemotor driven impelling member I6. In the present application there hasnot been shown the conventional and well known connection between theunit l5 and the cooling system of the motor vehicle. One of several wellknown and accepted manners of achieving this result may be resorted to,it being noted that the present illustration has been confined to thecooling of air rather than the raising of the temperature thereof.

The unit 15 may include any desired construction although it preferablyembraces the structures shown in Figs. 5 and 6. In the first of these,the numeral l'I indicates a core presenting a plurality of transversefluid conducting passages l8 .communicating at one end with an upwardlytapered head l9 and at their opposite ends with an upwardly flared head20. These passages are.

- as will be seen in Fig. 7 with top and bottom walls and 56, side walls52 and 54, and end walls, one of which appears at 5| in this view, whilejacent structures being disposed in parallel with the result that thepaths I8 extending horizon- V tally through the heat exchange unit aretortuous in character. It will be noted that the structures definingthese paths may soldering or otherwise securing the side edges 52 sideplates 52 and 54 might be so designed as to seal only the side edgesplates 50 and 56, provided opening is made for that purpose in the sideplates 5| and 54. Located passage 2| sages separated horizontally and indifferent heads although this need not necessarily be the f case, and ifdesired a unit such as shown in Fig. 6.may be employed. The latter unitalso includes passages 23 communicating at one of their ends with a head24. and attheir opposite ends with a head 25. The latter head is formedwith a central partition 26 and in its lower end has an inlet 1 tube21,.while at its upper end an outlet or discharge opening 28 is present.served in connection with Figs. 5 and 7, the heat transfer unit shown inFigs. 6 and 8 may be assembled by spacing horizontally extending boxlikestructures for top walls 5| andbottom walls 58, and end walls, 59 and60,'the latter showing only in Fig. 6. Side walls 6| and 64 are alsoprovided for these box-like structures which are been pointed out inconnection spaced horizontally one above the other to'provide aplurality of passageways 23. In addi- 'stion, each of the horizontallydisposed box-like structures is formed'with parallel sides of angularlydisposed sections reaching maximum points as is shownin 6 1 and 68. Theadjacent surfaces of said structures are complementary in character sothat atortuous path or passageway 23 is provided in each instance. Theside walls of said equally spaced corresponding sections 66 extendingdownwardly, complementary portions of adbe secured to the outer sides ofthe heat exchange unit 53 and 55 by:

As before. ob'

v and 54 thereto. Also, it is to be observed that the i of thepassage-ways l8 1 in the heat transfer unit, thus permitting pas- Ysageways for liquid or air to extend between the in the lower portion ofthe first head is an intake while an outlet passage 22 is disposed inthe upper end of head 20. A core assembly of this .character ispreferably disposed with pas- 1 In certain respects, however,

from this assembly an the inletand outlet openings of the core assemblyare disposed in opposite corners of the same and as has been shown inFig. 5 a tube 36 will connect with the lower end of body 3| and couplethe same totube 30.

Extending from the upper end of body 3| is a tube or pipe 31 which iscoupled to 'asuitable pump 38 driven by the fan belt 39 of the motor, orby any other suitable power source. The outlet of the pump is connectedto a condenser 40 which in turn discharges into a tank 4|, the latterconducting the distillate through a tube 42 coupled to the lower end ofbody 3|.

The condenser-tank assembly may be provided with a filler plug 43through which the system may be charged with a refrigerant to the properlevel. It will also be noted that there extends nects with the return orinlet tube 30. This connection is preferably effected as shown in Fig.4, by employing a packing assembly 45 through which the pipe 44 passesinto the inlet tube ofv the core assembly and adjacent the lower end ofthe same. At this point it is preferred that the pipe terminate in anend portion having the characteristics of a nozzle 46, as'shownespecially in Figs. 5and 6, so that notalone is the air or vapordirected as desired, but also an expansionvalve effect is achieved. 1 y

In operation the system is charged in any desired manner as aforeindicated and the plug 43 seals the tank. The refrigerant may be one ofa number of commercially available substances.

it is preferred to employ methylene chloride, commonly known as Carene,inthat a material of this type is noncaustic, non-corrosive, andfireproof, and also has the advantage that it is not injurious to human1 beings even if a leak should develop and the structures may be securedto the sides of the heat transfer unit at 10 and 1|.

with Figs. 5 and 7, both the'side walls 10 and 1| as well as side walls6| and 64 may be omitted for a substantial portion of their length toprovide transverse passages for other fluid or air, while at the sametime, keeping such transverse passageways separate and distinct from themain chamber of said heat transfer unit. The functioning of both ofthese core assemblies will hereinafter be more particularly considered.Suffice which is probably best shown in Fig. 3. In this view it will benoted that a float 32 is positioned within the body and when the liquidlevel within the core assemblies is at proper height this float,

As has heretofore it to say that if they, are being employed for thepurpose of cooling, a

i If methylene chloride is that at atmospheric frigerant will condenseat a vapors should be ihhaled.

With the pump 38 in operation a vacuum of, for example, 15 to 20 incheswill occur within tube 31. employed, it will be found pressure it boilsat atemperature of substantially 104 F. With 10 inches of vacuum itboils at a temperature of F. If, however, air is permitted to flowthrough the body of liquid, it will be found that, the boiling effectcontinues until a temperature of 58 F.

is reached. .Of course, when the vacuum is increased above 10 inches,this effect continues at muchlower' temperatures. Conversely, theretemperature of substantially 104 F. at atmospheric pressure. However,under 5 lbs. pressure, it will condense at a temperature of F. while ifthe pressure is stepped up to 10 lbs. above atmospheric, the

methylene chloride will condense at a tempera-.

ture of F. I Thus, with a vacuum exerted by pump 38 through tube 31 thetemperature of the fluid within unit 50 will reduce rapidly in that itwill quickly absorb heat, this being especially true with air passedthrough the 'body of liquid 'as afore brought out.

towards the pump 38. Necessarily, a certain air pipe 44 which con-Consequently vapor surcharged with refrigerant flows through tube 31amount of the refrigerant liquid will be entrained within this vapor andit would be extremely objectionable if these liquid particles were drawninto the pump. This is prevented, however, incident to the body 3| whichin certain respects acts as a trap. In this connection tube 29 or itscontinuation opens into the body 3| at a lower level than the entranceof tube 31 and at an angle to the axis of the latter tube. Consequentlyentrained particles of moisture will fall downwardly into the body 3|and serve to maintain the float 32 in raised position. Thus valve 34will remain closed. If, however, the level within this body drops belowthat which is proper, valve 34 will open and additional refrigerant willbe free to flow from the condenser-tank assembly through tube 41 intobody 3| under the influence of the pressure existing within thecondenser-tank assembly, it being understood that this pressure hasassisted and accelerated the condensing of the refrigerant.

In this manner the level will at all times be properly maintained. Vaporwill be discharged through-pipe M and incident to the pressure whichthis vapor is under the air will probably be surcharged withrefrigerant. Incident to the expansion valve effect achieved by thenozzle 46 or otherwise, the air will, of course, expand upon enteringthe unit l5 and will be free to absorb additional vapor, thusaccordingly lowering the temperature of the refrigerant within the unit.

Considering the construction of unit present in Fig. 5, it will beobserved that the air or vapor discharged through nozzle 46 will rapidlyrise through the refrigerant within head 19 and will flow throughtheupper courses of passages It! to head 20. In so doing it will, ofcourse cause a cooling of the refrigerant and the latter, incident tothe resultant thermo-dynamic cycle, will rotate or circulate in aclockwise direction as indicated by the arrows. The vapors will be drawnthrough outlet 22 and distributed as afore described, and the fan orimpeller IE will be passing air through the spaces in interveningpassages Hi.

In the case of a structure shown in Fig. 6 the air will again bedischarged from the nozzle 46, will flow upwardly within head 25 and inadvance of the partition 26 will flow through passages 23 to head 24.Through the latter it will rise until it may pass above the refrigerant,back to head 25, and so through the outlet 28. In this latter form ofconstruction the refrigerant situated generally below partition 26 willcirculate in a counter-clockwise direction, while that above thepartition will circulate in a clockwise direction.

Thus, in both forms of unit the air will evenly cause a'cooling ofallparts of the liquid body in that during a given interval of time acomplete cycle of fluid circulation will occur. Also, in both forms ofthe apparatus it will be appreciated that adjacent substantially thehighest liquid level the flow of air through the passage will enhance toa large extent the refrigerating effect.

It will, of course, be understood that the liquid level need notnecessarily be maintained as indicated in Figs. 5 and 6. In fact, incertain instances where it is desired to reduce'noise, the liquid levelmay be sufliciently high to permit of a certain quantity of the liquidflowing through the outlet pipe. In that event, it will be appar nt thatthe liquid will simply flow to the float chamber and be returned throughthe inlet pipe and the operation of the system will not be interferedwith.

Thus, among others, the several objects of the invention as afore notedare achieved. Obviously, numerous changes in construction,andrearrangement of the parts, might be resorted to, without departing fromthe spirit of the invention as defined by the claims.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. A heat transfer unit to receive a body of liquid and through whichbubbles of gas are to flow upwardly, said unit including acorepresenting substantially horizontally extending tortuous passages,vertically extending head members disposed adjacent each end of saidcore and having communication with said passages, said unit being formedwith an inlet opening adjacent the lower end of one of said head membersand an outlet opening formed adjacent the upper end of one of said headmembers, means for maintaining the height of the body of liquid withinsaid unit below the plane of said outlet opening, and the head member ofwhich said inlet opening forms a part being tapered upwardly whereby toinduce a flow of bubbles through said head member toward said passagesand below the upper level of the liquid body before said bubbles mayescape to said outlet opening.

2. A heat transfer unit to receive a body of liquid and through whichbubbles of gas are to flow upwardly, said unitv including a corepresenting substantially horizontally extending tortuous passages,vertically extending head members disposed adjacent each end of saidcore and having communication with said passages, said unit being formedwith an inlet opening adjacent the lower end of oneof said head membersand an outlet opening formed adjacent the upper end of one of said headmembers, means for maintaining the'height of the body of liquid withinsaid unit below the plane of said outlet opening, the head member withinwhich said inlet opening is formed being tapered in an upward directionand toward said passages, the outlet opening being formed in theopposite head member and adjacent the upper end of the same, said lattermember being flared upwardly whereby the bubbles may fiow .upwardlythrough the first named head member and will be diverted through saidpassages below the upper level of said liquid body and may thence flowthrough-said outlet opening.

3. A heat transfer unit including a core comprising substantiallyhorizontally extending passageways, each passageway embracing equallyspaced sections angularly disposed to the horizontal, and alternatingupwardly and downwardly with respect thereto, such sections providing atortuous path in said passageways, head members connected to the ends ofsaid passageways and disposed in generally vertical planes, pipesconnected to said unit and for causing a flow of fluid through the same,and circulation causing means in ahead member, said head members beingformed to cooperate with said circulation causing means to induce acirculation of liquid throughout said passageways and head members assaid fluid flows through said unit.

CARL E. MEYERI-IOEFER.

. l l I

